Abrupt discontinuation of cycled parenteral nutrition is safe

Abrupt discontinuation of total parenteral nutrition (TPN) has been recommended but is not widely practiced because of fear of hypoglycemia. To determine whether hormonal counterregulatory mechanisms prevent hypoglycemia, we studied 12 patients (10 with inflammatory bowel disease, of which 6 received dexamethasone) after both abrupt and tapered discontinuation of 3:1 TPN solution in a clinical research facility. Venous blood was drawn before reduction of TPN rate in the tapered group or 15 minutes before and at abrupt discontinuation in the abrupt group and every 15 minutes for 1.5 hours. Glucose decreased from 152 +/- 56 (baseline) to 100 +/- 22 mg/dl 90 minutes after gradual discontinuation of TPN, compared with 135 +/- 45 to 96 +/- 15 mg/dl at 90 minutes after abrupt discontinuation, with no significant differences in mean glucose values. Mean epinephrine, norepinephrine, insulin, glucagon, growth hormone, cortisol, symptom score, and vital signs were not statistically different between the two groups. Hypoglycemia does not occur after abrupt discontinuation of TPN. The same changes in counterregulatory hormones were seen whether discontinuation was tapered or abrupt. In stable patients, TPN solutions can be abruptly discontinued.